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what is the maximum size of an array?

> Thank you. I was already looking into using a global array, but was
> having difficulty figuring out how globals work in L.V.
>
> One question I have, though, is what is a "LV2 style global?" How are
> they different from the globals found in the "structures" menu in LV6?
> And how do I create a LV2 style global?
>

A LV2 style global is a funny name for putting a function
interface around global storage. It is quite different
than the globals in the palette. The globals in the
palette are good for scalars and small values, but they
allow you to read and write the entire value, and that
is it. If you read the entire value, modify an element,
then write the value back to the global, you have copied
the data and opened yourself up for a
race condition.

A LV2 style global, is a subVI that internally updates
the global data, typically stored in an uninitialized
shift register. The subVI has a parameter that controls
whether it is a read operation, a write operation, an
initialized operation, or whatever. It can have inputs
for indexing an element to update or to read. It can
perform analysis on the array or whatever else needs
to have limited access to the global. This subVI means
that the LV compiler is guaranteed that only one place
in the whole application can write to the shift register
and modify the array. This allows LV to be pretty
optimized about the data copy. It means that you can
place any type of interface you like on the subVI.

For examples of a LV2 style global, look at examples/
globals.llb/smart global.vi, in particular, the Smart
Buffer(DBL).vi.


Greg McKaskle
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Im using a two dimension array having the limitation of 17000 colloumn and 4096 rows and which i save as a spread sheet file. while using this much size my application is very slow.

Is there are any options to handle through spread sheet in labVIEW?

How to allocate dynamic memory for this two dimension array?

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First, you are responding to a thread which is 8 years old.  You probably would have been better off starting a new one. 

 

Spreadsheet files are text files so the numeric values need to be converted to text.  With almost 17 million elements that is a lot of conversion.  The files will be around 0.5 GB, depending on the format or how many characters per element will be saved.  A binary format might be better.

 

Search for a white paper on Handling Large Datasets.  That has lots of good information about memory allocation for large arrays. 

 

Lynn 

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